Teardrop sealant layer for profile and spacer areas for improved sealing and guiding
A reclosable zipper for use with package, such as food and non-food packages, that include first and second mating profile members. Each of the first and second profile members of the zipper closure includes a pair of flanges each having a sealant layer. The sealant layer formed on each of the flanges protrudes past the outer surface of the flange such that the outer surface of the sealant layer contacts the film of web material. The sealant layer is formed from a material different than the material that forms the remaining portions of the first and second profile members such that the sealant layer melts and forms a bond with the web material upon the application of heat. Each of the profile members includes a standoff area formed along the inner surface of each flange to provide support for the flange during the application of the heating element.
The present invention generally relates to the reclosable zipper for the application between a pair of side panels of a reclosable package. More particularly, the present invention relates to a reclosable zipper that includes a sealant layer on the flanges of both a first profile member and a second profile member to facilitate attachment of the reclosable zipper to the side panels of a reclosable package.
BACKGROUND OF THE INVENTIONIn the field of packaging, particularly in the area of food packaging, it is often desirable to package items in a package that may be repeatedly opened and closed. For example, when dealing with packaged foods, the consumer may initially use only a portion of the food contained within one package. By providing a package that may be reclosed by the consumer, the consumer avoids having to locate a storage container for the unused portion of the food in the package. It will be appreciated that reclosable packaging enhances the marketability of such products.
To facilitate the manufacturing of packages including a reclosable seal, the reclosable seal is often provided in the form of a continuous profile strip that may be manufactured independently from the package itself. The profile strip is typically wrapped onto a spool or reel for storage until it is needed to complete the packaging process.
When a product is packaged, the profile strip is unwound from its storage spool and attached to the packaging substrate during the packaging process. Typically, the profile strip is attached to each of the side panels of the product package by heating a flange on each of the pair of mating profile members and the side panels of the bag simultaneously. Because both the profile members and the bag material are typically formed from the same material, such as polyethylene, the two components melt together forming a sufficient seal.
One disadvantage of the use of a heated sealing bar to attach the first and second profile members of a profile strip to the opposite panels of a reclosable bag is that during the heating process, the generally planar flanges of each of the first and second profile members can be distorted due to the heating process.
Reclosable zippers having one or more fusible ribs for sealing the zippers to the package material are known in the reclosable packaging art. Such zippers are found in U.S. Pat. Nos. 4,673,383, 5,216,787 and 5,242,516.
Although the prior art shows examples of fusible ribs and sealant layers used to attach a profile strip to a reclosable package, the configuration and construction of the profile strip requires improvement.
SUMMARY OF THE INVENTIONThe present invention is directed to a zipper closure for use along a mouth of a flexible, reclosable package. The zipper closure is preferably formed as a continuous strip during an extrusion process and is subsequently applied between the first and second panels of a reclosable package, such as with a form, fill and seal (FFS) machine.
The zipper closure of the present invention includes first and second mating profile members that each include a base and an interlocking closure element extending from the base. The first and second profile members are configured such that the interlocking closure elements of each engage each other to hold the first and second profile members in an engaged, closed position. Both the first profile member and the second profile member include a pair of flanges that each extend from the base of the respective profile member. The flanges are used to attach the respective profile member to opposite side panels of a flexible web used to create the product package.
Each of the flanges includes an inner surface and an outer surface. The outer surface of each flange faces the web material used to form the product package. In accordance with the present invention, the outer surface of each flange includes a sealant layer formed near the outermost edge of the flange. The sealant layer has a generally teardrop shape and includes an outer surface that protrudes away from the generally planar outer surface of each flange. Thus, when the first and second profile members are brought into contact with a layer of web material, the outer surface of each of the sealant layers contacts the inner surface of the web material. In this manner, an open air gap is formed between the layer of web material and the outer surface of the base of each of the first and second profile members.
Each of the sealant layers can be extruded with the remaining portions of the first and second profile members. The sealant layers are preferably formed from a second material while the remaining portions of the first and second profile members are formed from a first material. Preferably, the first material is a low density polyethylene, while the second material that forms the sealant layer is an EVA sealant layer that melts at a lower temperature than the low density polyethylene.
Each of the first and second profile members includes at least one standoff area formed on the inner surface of each of the flanges of the profile members. Each standoff area extends away from the otherwise planar inner surface of the flange such that each of the standoff areas extends toward the opposing profile member. Preferably, each of the standoff areas are formed near the outermost edge of the respective flange such that each of the standoff areas are generally aligned with one of the sealant layers. During the application of the zipper closure to the web material, each of the standoff areas contacts a zipper guide plate to provide support for the sealant layer during the pressure application of a heated sealing bar. The interaction between the standoff areas and the guide plate prevents deflection of the flanges and aids in the attachment of the sealant layers to the web material.
BRIEF DESCRIPTION OF THE DRAWINGS
As shown in
As illustrated in
In many applications, the zipper closure 26 is formed using an extrusion process, as will be described in much greater detail below, and is provided as a continuous strip of material wound onto a roll or spool and is provided packaging facility. Once in the packaging facility, the continuous strip of the zipper closure 26 is applied between opposing sheets of a flexible web in a form, fill and seal (FFS) machine. While in the form, fill and seal machine, the first and second profile members 30, 32 are attached to the opposing side panels 12, 14 using a heat application process. During the same process, the side edges 18, 20 are also formed through the application of heat.
Referring now to
The mating second profile member 32 also includes a base portion 46 having an interlocking closure element 48 extending therefrom. In the embodiment illustrated in
As illustrated in
The second profile member 32 also includes a pair of flanges 58 integrally formed with the base 46. Each of the flanges 58 includes an inner surface 60 and an outer surface 62. The outer surface 62 of each flange is generally coplanar with an outer surface 64 of the base portion 46. In the embodiment of the invention illustrated, one of the flanges 58 of the second profile member 32 includes an upstanding sealing flange 66 that is typically positioned toward the open interior of the package and aids in providing a seal across the open mouth of the product package.
In the embodiment of the invention illustrated, the flanges and base portion of both the first and second profile members 30, 32 are formed from the same material, such as a low density polyethylene. This type of material is typically used in the formation of an interlocking zipper closure 26. Although low density polyethylene is shown and described in the preferred embodiment, other similar materials are contemplated.
As illustrated in
As illustrated, the second profile member 32 also includes a pair of sealant layers 74 formed near the outermost edge 75 of each of the flanges 58. Each of the sealant layers 74 is also teardrop shaped and includes an outer surface 76 that protrudes outwardly of the outer surface 62 of each of the flanges 58 and the outer surface 64 of the base 46.
In the embodiment of the invention illustrated in
Referring back to
The second profile member 32 also includes a pair of standoff areas 80 formed on each of the flanges 58. Each of the standoff areas 80 protrude from the inner surface 60 of the flanges 58 and toward the mating first profile member 30 when the profile members are in the mated condition shown in
Referring now to
As illustrated in
Likewise, the inner surface 106 of the second web 102 contacts only the outer surface 76 of the sealant layers 74 formed on the flanges 58 of the second profile member 32. The contact between the sealant layers 74 and the inner surface 106 provides a space between the inner surface 106 and the outer surface 62 of the flanges 58 and the outer surface 64 of the base portion 46.
Referring now to
As illustrated in
Referring now to
As illustrated in
As illustrated in
Referring back to
Having described the presently preferred embodiments, it is to be understood that the invention may be otherwise embodied within the scope of the appended claims.
Claims
1. A reclosable zipper comprising:
- a first profile member having a base, an interlocking closure element extending from the base and at least one flange extending from the base, the flange having an inner surface and an outer surface;
- a second profile member having a base, an interlocking closure element extending from the base and at least one flange extending from the base, the flange having an inner surface and an outer surface;
- a sealant layer formed on the outer surface of at least one flange of the first profile member and the second profile member, the sealant layer protruding from the flange; and
- a standoff area formed on the inner surface of the flange having the sealant layer.
2. The reclosable zipper of claim 1 wherein the standoff area is generally aligned with the sealant layer.
3. The reclosable zipper of claim 1 wherein the first profile member and the second profile member are formed from a first material and the sealant layer is formed from a second material.
4. The reclosable zipper of claim 3 wherein the second material is a heat activated adhesive.
5. The reclosable zipper of claim 3 wherein the standoff area is formed from the first material.
6. The reclosable zipper of claim 1 wherein the sealant layers are extruded with the first and second profile members.
7. The reclosable zipper of claim 1 wherein the sealant layer has a generally teardrop shape.
8. The reclosable zipper of claim 1 wherein each flange includes an edge spaced from the interlocking closure element, the sealing layer being formed on the edge of the flange.
9. The reclosable zipper of claim 1 wherein the sealant layer is formed on the flanges of both first profile member and the second profile member.
10. The reclosable zipper of claim 1, wherein the first profile member includes a pair of flanges and the second profile member includes a pair of flanges.
11. The reclosable zipper of claim 10 further comprising a pair of standoff areas formed on the inner surface of each flange of both the first profile member and the second profile member.
12. The reclosable zipper of claim 11 wherein each of the standoff areas is generally aligned with one of the sealant layers.
13. The reclosable zipper of claim 10 wherein the pair of flanges on the first profile member extend in opposite directions from the base of the first profile member and the pair of flanges of the second profile member extend in opposite directions from the base of the second profile member.
14. A method of attaching a reclosable zipper to a web of material, the method comprising the steps of:
- providing a first profile member having a base, an interlocking closure element extending from the base and a pair of flanges extending from the base, each flange having a sealant layer formed on an outer surface of the flange and a standoff area formed on an inner surface of the flange;
- providing a second profile member having a base, an interlocking closure element extending from the base and a pair of flanges extending from the base, each flange having a sealant layer formed on an outer surface of the flange and a standoff area formed on an inner surface of the flange;
- moving the first and second profile members into a profile guide having a first guide element and a second guide element, wherein the first and second guide elements are positioned between the flanges of the first profile member and the second profile member, wherein the standoff area formed on each of the first and second profile members contacts the respective first and second guide members;
- positioning the web of material adjacent to the sealant layer formed on both of the first and second profile members;
- moving a heated sealant bar into contact with the web of material to melt the sealant layer formed on both the first profile member and the second profile member, wherein the standoff area formed on each of the flanges of the first and second profile members supports the flange against the guide member.
15. The method of claim 14 wherein the standoff areas are each generally aligned with one of the sealant layers.
16. The method of claim 14 wherein the sealant layer is extruded with each of the first and second profile members.
17. The method of claim 15 wherein the heated sealing bar melts only the sealant layer and does not deform the base of either the first profile member or the second profile member.
18. A reclosable zipper comprising:
- a first profile member having a base, an interlocking closure element extending from the base and a pair of flanges each extending from the base, each flange having an inner surface, an outer surface and an edge spaced from the interlocking closure element;
- a second profile member having a base, an interlocking closure element extending from the base and a pair of flanges each extending from the base, each flange having an inner surface, an outer surface and an edge spaced from the interlocking closure element; and
- a sealant layer formed on the outer surface of at least one flange of both the first profile member and the second profile member, each sealant protruding from the outer surface of the flange.
19. The reclosable zipper of claim 18 wherein the first profile member and the second profile member are formed from a first material and the sealant layers are formed from a second material.
20. The reclosable zipper of claim 18 wherein each of the sealant layers has a generally teardrop shape.
21. The reclosable zipper of claim 18 wherein each flange of the first profile member includes a sealant layer and each flange of the second profile member includes a sealant layer.
Type: Application
Filed: Mar 25, 2004
Publication Date: Sep 29, 2005
Patent Grant number: 7216405
Inventor: Steven Gradl (Appleton, WI)
Application Number: 10/810,747